276 TEXTBOOK OF BOTANY 



the style. Here conditions are not favorable for its further 

 development ; the egg dies, and no gall is formed. Instead, 

 in the ovary of this flower a seed is produced, and the ovary 

 develops into a small, hard fruit. The short-styled flowers 

 of the fig seem to be of no direct use to the plant. Indirectly 

 they are useful, because they supply a place in which the 

 eggs of the wasp can hatch, and so the species of insect 

 which pollinates the plant is kept alive. The figs that con- 

 tain only long-styled pistillate flowers, and in which there- 

 fore fruits may be formed, are the ones that develop into 

 edible figs. Most of the figs that contain staminate and 

 short-styled pistillate flowers dry and fall early and so are 

 useless. It is customary among fig-raisers to plant an oc- 

 casional tree bearing figs of this latter sort, and branches of 

 this tree on which figs are growing are hung on the branches 

 of the trees that bear edible figs. This insures the polli- 

 nation of the long-styled flowers in the edible figs and the 

 development of seeds. 



The figs of some varieties will ripen in a perfectly normal 

 way even if none of their pistillate flowers are pollinated, 

 although of course they contain no fruits or seeds. The 

 figs of other varieties, however — including those which 

 supply the dried figs of commerce — will fall from the tree 

 before they are fully grown, unless their fiowers have been 

 pollinated. 



285. Cross-Pollination and Self -Pollination. — Cross- 

 pollination means the carrying of pollen from the anthers of 

 one flower to the stigma of another flower which may be on 

 the same or on a different plant. Self-pollination means the 

 carrying or dropping of pollen from the anthers of one flower 

 to the stigma of the same flower. There are peculiarities 

 in the structure of many flowers, both those of wind-polli- 

 nated and those of insect-pollinated plants, which make 

 self-pollination either impossible or much more difficult 

 than cross-pollination. The study of these peculiarities has 



